Modeling Tips

AERSCREEN View - Creating Modeling Scenarios

The AERSCREEN model is very efficient but it only processes a single source per run. To address this limitation, AERSCREEN View includes the Scenario Wizard which allows modelers to quickly create any number of model runs for analysis.

AERMOD View - Reading AERMOD SFC File Headers

AERMET, the meteorological preprocessor used to generate meteorological data for use in the AERMOD air dispersion model, creates two unique files:

• A surface file (*.SFC) containing surface-level variables and turbulence scaling parameters calculated by AERMET, and
• A profile file (*.PFL) containing multi-level variables for boundary layer profile analysis in AERMOD.

AERMOD View - Modeling NO2 in AERMOD – ARM2

One of the biggest changes to the AERMOD modeling system in the 18081 model update was the removal of the original Ambient Ratio Method (ARM) for analyzing conversion of NO_x to NO₂. This option, based on Chu & Meyer’s 1991 work presented at that year’s Air & Waste Management Association’s annual conference, used a single ratio to convert all NO_x concentrations to NO₂. The national default value was 75% for annual averages, and subsequent guidance recommended a value of 80% for the hourly standard.